I'm using Visual Studio 10.0.40219.1 SP1 Rel and I've just recently started having a problem with it. When I open a .aspx page to change any of the markup as soon as I start typing I get an error message that pops up that says

"Visual Studio has encountered an exception. This may be caused by an extension."

It then tells me I can see more details about the error by using the /log trigger and then look at the ActivityLog.xml. After the exception my intellisense doesn't work when I start typing

System.ArgumentOutOfRangeException: Index was out of range. Must be non-negative and less than the size of the collection. Parameter name: index at System.ThrowHelper.ThrowArgumentOutOfRangeException() at System.Collections.Generic.List1.get_Item(Int32 index) at System.Collections.ObjectModel.ReadOnlyCollection1.System.Collections.Generic.IList.get_Item(Int32 index) at Artem.VisualStudio.Outlining.OutliningTagger.CalculateChange(TextContentChangedEventArgs e) at Artem.VisualStudio.Outlining.OutliningTagger.HandleBufferChanged(Object sender, TextContentChangedEventArgs e) at Microsoft.VisualStudio.Text.Utilities.GuardedOperations.RaiseEvent[TArgs](Object sender, EventHandler`1 eventHandlers, TArgs args)

Under "Source" (in the ActivityLog.xml) they both say "Editor or Editor Extension".

I have tried disabling all the extension I have installed, but it doesn't make any difference. I'm on a Win7 64bit machine.

There are some posts I've seen relating to fixing a registry entry, but my registry entry already looks exactly right. I'm at a loss and I'm hoping someone has had a similar issue. Thank you in advance!

That could very well be related. It sounds like the same issue and I did install a plugin for jsoutlining. I also disabled and then uninstalled it, but the issue still remains. The only extension I have installed right now is the Enterprise Library, but that has worked great since it was installed.
–
CoryAug 30 '12 at 18:13

Could you have a physical look into the {VS2010_INSTALL_DIR}\Common7\IDE\Extensions folder? just to be sure :D
–
azhwkdAug 30 '12 at 18:19